The invention is based on a priority application EP 05291883.6 which is hereby incorporated by reference.
The invention relates to a transceiver module for an optical data network, comprising an optical interface for connection with an optical transmission line and an electrical interface for connection with a host board, wherein the electrical interface is suitable for providing the transceiver module with payload data to be sent on the optical transmission line and for providing the host board with payload data read from the optical transmission line, and further comprising monitoring means for monitoring the optical transmission line.
The invention further relates to a method for making available measuring data from monitoring an optical transmission line coupled to an optical transceiver module.
Such a transceiver module is known from the European patent application 04 291 995.1, scheduled to be published after the submission of this application.
In order to transmit digital data, optical networks are used. An optical network comprises optical transceivers which are linked by optical transmission lines, in particular optical fibers.
It is common to realize optical transceivers with optical transceiver modules. An optical transceiver module is a device for converting electrical signals carrying payload data, received at an electrical interface, into optical signals, which are sent onto an optical interface (where an optical transmission line is attached), and for converting optical signals, received at the optical interface, into electrical signals. The payload data, no matter whether contained in received electrical signals or contained in received optical signals, is only passed on, without any analysis of the payload data such as error analysis or error correction within the transceiver module.
The transceiver module is typically linked to a host board, where data to be sent and received data are processed and analysed.
Unfortunately, optical fibers may become defective. A defect may cause a loss of data. For this reason, the status of an optical fiber in an optical network must be monitored. A well known monitoring method is OTDR (optical time domain reflectometry). In this method, a short optical pulse is sent onto an optical fiber, through which it propagates. At locations of defects, such as a sharp bend within the optical fiber, light of the optical pulse is particularly strongly backscattered. The time between the sending the pulse and receiving a peak of backscattered light indicates the location of the defect.
From the above mentioned European patent application, it is known to integrate equipment for an OTDR measurement, in particular a tap coupler, a photo diode and an OTDR signal output, into an optical transceiver module. The ODTR signal is passed on, without any signal analysis, to a failure detection means externally of the transceiver module via the OTDR signal output.
In order to learn about the state of the optical fiber, in this state of the art, a large amount of data must be transferred over the OTDR signal output. Further, the installation of the optical transceiver module requires linking both a data interface and an ODTR signal output.